Robust full-field modal testing method for structural health monitoring of aerostructures under random noise

The robustness of a new modal testing method is investigated, based on the posterior treatment of the well-established inverse finite element method (iFEM) with Fourier transformation for mode identification and mode reconstruction of shell/plate structures. This post-treatment iFEM method, named iFEM mode reconstruction (iFEM-MoRe), is capable of both identification and reconstruction of modes for any structure when discrete sensor data is available. The computational framework of iFEM-MoRe is confirmed to be robust by comparing the natural frequencies of a rectangular plate, consisting of isotropic material, by performing several numerical analyses with different load and damage cases to address the well-known robustness issues. The method is found to be robust with these numerical studies. The pristine modal characteristics are estimated with an error smaller than 2.17%. Also, both damage identification and localization are robustly achieved.